The present invention relates generally to the field of producing sanitary-engineering items and has particular reference to installations for applying a coat to the entire inner surface of sectionalized hollow items.
The present invention can find use for application of a coat to the entire inner surface of hollow items having at least one internal partition that divides the interior thereof into an entry and an exit portions having an inlet and an outlet opening, respectively. The invention is likewise practicable to be employed for applying glaze-coating to the inner surface of sanitary-engineering items, such as lavatory basins, bidets, etc.
The present-day state of the art knows a number of installations for applying a coat to the inner surface of sanitary-engineering items and some other stoneware.
To take an example, one prior-art installation for glazing white earthenware is known to comprise a rotor for dipping the items under treatment, said rotor having holders to grip the latter, and a glazing bath, the dipping rotor being followed by a drying rotor, and a swing pusher is provided between both of the rotors.
The afore-discussed installation operates as follows. The item to be glazed is pushed-fitted onto the dipping rotor rods by a chain feeder, whereupon the item is dipped in the glazing bath. Upon leaving the glazing bath the item is forwarded to the pusher which pushes over the item from the dipping roller rods onto the drying rotor rods. Further on, the item slips off the drying rotor rods to get onto the receptacle conveyor.
However, the abovementioned installation has the disadvantage that it makes use of a traditional technique for coating sanitary-engineering items, i.e., by dipping which is disadvantageous in failing to provide a uniformly spread coating, presence of glaze stains and runs, inability to obtain a coat thick enough due to a relatively low density of the glaze used in such method, and the like.
One more prior-art installation for glazing hollow stoneware is known to currently use, a carriage for items to be glazed provided with its traversing mechanism, a glaze sprayer device with its traversing mechanism, a glaze catcher pan with its traversing mechanism, and a tipper mechanism for items under processing, provided with an arresting device to fix the item being treated in position while being tipped over, fixing being attained due to clamping the item in between hold-downs traversable from above downwards by air-operated cylinders, and the carriage bearing surface.
The installation discussed above operates as follows. The item to be glazed is fed by the carriage under the glass sprayer device, the glaze catcher pan is moved aside, while the glaze sprayer is sunk into the bowl of the item under processing; concurrently, glaze starts to be fed to the sprayer device. Next the glaze sprayer is raised, the glaze catcher pan is placed in position and the tipper turns over the item so as to let surplus glaze run down. This done, the tipper returns the item into the initial position, whereupon the hold-downs are actuated by their air cylinders to release the item.
However, the construction of the installation fails to provide the production of quality finished items featuring fully glazed inner surfaces, which may be attributed to the following reasons:
1. construction of the tipper mechanism involves the provision of special arresting devices to retain the items in place by forcing them against the swivel platform while being tipped over which, apart from substantial siphistication of the construction, is inescapably causative of collapsing the items under treatment that is liable to occur rather infrequently due to permissible and actually encountered scattering of height dimensions thereof, i.e., items featuring the height dimension in excess of the rated value get crushed while being held down, whereas those with the height short of the rated value fail to be held in place and thus fall out while being tipped over.
2. The inner surface of the siphon (or trap) of the basin fails to be glazed due to an air lock formed in the top portion of the trap and owing to the absence of a special device for glazing said surface, which is inadmissible.
3. No provision of any means masking the outer surface of the item under treatment in the installation results in that the drops and runs of the glaze make their way onto the outer surface, thus affecting adversely the trade appeal and quality of the finished items.